// Spun AJAX Framework
// Copyright (C) 2008 Blake Hegerle
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace Formality.FormalSystem
{
    public class PrefixOperator : TermOperator
    {
        public PrefixOperator(string Operator, IEnumerable<Proposition> Operands)
            : base(Operator, Operands)
        { }

        public PrefixOperator(string Operator, params Proposition[] Operands)
            : this(Operator, (IEnumerable<Proposition>)Operands)
        { }

        protected override TermOperator NewOfThisType(IEnumerable<Proposition> Operands)
        {
            return new PrefixOperator(OperatorSymbol, Operands);
        }

        public static string Paren(Proposition Proposition)
        {
            if (Proposition is InfixOperator)
                return string.Format("({0})", Proposition);
            else
                return Proposition.ToString();
        }

        #region Sentence overrides
        public override void Serialize(TextWriter Writer, bool Detailed)
        {
            Writer.Write(OperatorSymbol);

            var OpIter = Operands.GetEnumerator();

            var More = OpIter.MoveNext();

            while (More)
            {
                var ShouldParenthesize = OpIter.Current is InfixOperator;

                if (ShouldParenthesize)
                    Writer.Write("(");

                OpIter.Current.Serialize(Writer, Detailed);

                if (ShouldParenthesize)
                    Writer.Write(")");

                if (More = OpIter.MoveNext())
                    Writer.Write(" ");
            }
        }
        #endregion
    }
}
